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HomeMy WebLinkAboutLake_Cornelia_Summarycommon carp (invasive) A feasibility study is completed and recommends a variety of management activities, including alum treatment, aeration, sh management, and stormwater ltration. History of Lake Cornelia Lake Cornelia is a shallow lake with northern and southern basins connected by storm pipes. 1960s1930s 2021 North Lake Cornelia 100 62 Stormwater runoff received from 112-acre area. 100 62 Southdale Shopping Center Southdale Shopping Center 1898 Lake Cornelia appears on Edina’s plat map as part of a natural wetland. 1978 The MN DNR issues a permit for the control of submerged aquatic plants. These efforts continue until 2015, when Edina's Lake and Pond policy is implemented. 1929-1941 With the arrival of farmers, area wetlands are drained. Lake Cornelia appears dry at times due to drought conditions. 2016, 2020, 2021 NMCWD monitors algal levels within the lake and observes high levels of blue-green algae. Blue-green algae can produce toxins that may irritate the skin or be harmful if ingested or inhaled. NMCWD and the City issue public alerts to stay out of the water until conditions improve. 2018 Based on observed phosphorus concentrations, the Minnesota Pollution Control Agency lists South Cornelia as impaired due to excessive nutrients. 2020 Agencies study the lake to determine the sources of pollution and assign responsibility for water quality improvements. This is a called a Total Maximum Daily Load study, required by the Minnesota Pollution Control Agency Lake Cornelia Algae Level (Chlorophyll-a) Water Clarity Total Phosphorous Levels Watershed District: Nine Mile Creek Public water ID: 27002800 2010 Water quality study completed by NMCWD 2019 Lake study updated 2015-2016 Lake Cornelia Lake Group formed Lake Management Learn more about these strategies at ninemilecreek.org Aquatic Plants Diverse aquatic vegetation is critical to the health of Edina lakes—providing food and shelter for sh and waterfowl and improving water quality. Invasive plant species within the lake are shown above. Curly-leaf pondweed further contributes to the lake’s problems. The invasive, non-native aquatic plant grows under the ice during the winter and in early spring, often crowding out native species. It dies in late June and early July, much earlier than other native species. As curly-leaf pondweed decays, phosphorus is released into the water, fueling algal production. Eurasian watermilfoil is a rooted, submerged aquatic plant, and purple loosestrife is a colorful, perennial wetland plant. Both species outcompete native plants, and neither provides suitable shelter, food, or nesting habitat for native animals. Water LevelsWater Quality Water quality data for six of the years between 2013 and 2020 is available from the Nine Mile Creek Watershed District and the Metropolitan Council's Citizen-Assisted Monitoring Program. Summer-average highs and lows of water quality parameters over those years are provided above. Lake Cornelia has poor water quality. Both basins are on Minnesota’s impaired waters list for excess nutrients. The poor water quality is primarily due to excess phosphorus in the lake. The phosphorus comes from many sources, including stormwater runoff, decaying plants, and nutrient-rich sediments. Bottom-feeding sh also stir up this sediment, releasing phosphorus and creating murky water. 2021 Construction of the Rosland Park stormwater ltration system. The project removes phosphorus from watershed runoff. 2020 South Cornelia Buffer Restoration: Project to restore the shoreline and plant a buffer of native plants completed. May 2020 Alum Treatment: An in-lake alum treatment is performed to control phosphorus release from lake-bottom sediments. 2017 Curly-leaf pondweed treatments: Beginning of annual spring herbicide treatments to control curly-leaf pondweed. Reducing curly-leaf pondweed can improve the native aquatic plant communities and reduce phosphorus levels. 2021 Fish Management: Continued goldsh and carp studies evaluate management methods to minimize lake sediment disturbance. 2008 The Minnesota Pollution Control Agency adds North Lake Cornelia to a national inventory of waterbodies that are not meeting water quality goals because of high phosphorus levels. Recent water quality data North Cornelia South Cornelia 1842 Mckinley Street NE Denotes current Lake Cornelia drainage area; historical drainage areas may have varied 1950s Suburban growth gives rise to Southdale shopping center, the expansion of highways, and more impervious areas. Storm sewer drainage systems alter the watershed, bringing more runoff and pollutants to the shallow lake. 1960s The Edina City Manager receives a recommendation from City staff to control "weeds" in Lake Cornelia. black crappie green sunsh Stormwater runoff received from 863-acre area 19 acres (surface area) 31 acres (surface area)Amenities:A pavilion, a picnic shelter, tables, grills, a 1.1-mile paved path, and a shing pier. Rosland Park, adjacent to Lake Cornelia, has baseball elds, a disc golf course, a playground, pickleball courts, and tennis courts. There are no public swimming beaches at Lake Cornelia. Non-motorized boats only. bluegill sunsh goldsh (invasive)yellow perch Native and invasive sh population: Other species present: golden shiner, pumpkinseed Lowest recorded water level 858.4 ft (Nov. 30, 2012) Highest recorded water level 862.3 ft (Apr. 30, 2014) Lowest recorded water level 858.1 ft (Nov. 30, 2012) Highest recorded water level 859.6 ft (Jun. 29, 2020) North basin 3 ft Mean 7 ftMax 5 5 44 4 ftMin 197 174 72 84 97 20 g/L State goalsNorthSouth (South’s highest recorded clarity) (North’s highest recorded clarity) (North & South’s lowest recorded clarity) 97 36 How You Can Help Steps that you can take to help Lake Cornelia include: South basin 4 ft Mean 8 ftMax ftMin 7 7 66 6 55 hybird sunsh black bullhead As part of Minnesota DNR’s Fishing in the Neighborhoods (FiN) program, the lake is stocked with 120 adult bluegill sunsh to provide shore-shing opportunities in metropolitan areas. 60 g/L NMCWD = Nine Mile Creek Watershed District Curly-leaf pondweed Purple loosestrife Eurasian watermilol31 Interactive ood map Water resources library Find more information from the City of Edina: 2012-2022 North Cornelia water level data is from Nine Mile Creek Watershed District. 1964-2002, 2012-2022 South Cornelia water level data is from Minnesota Department of Natural Resources and Nine Mile Creek Watershed District. Installing rain gardens and planting shoreline buffers Cleaning up grass clippings and leaves Participating in the adopt-a-drain program (mn.adoptadrain.org) Redirecting gutter downspouts towards vegetated areas Minimizing use of fertilizer on lawns Efforts to control submerged aquatic plants 2015 General submerged aquatic plant treatments stop with the implementation of Edina’s Lakes and Ponds policy, which prioritizes treatment based on a series of factors, including water body size, level of impairment, citizen involvement, and public use. 1.0 Meters 0.2 Meters 0.6 Meters 0.8 Meters South Lake Cornelia